1. Field of the Invention
The subject disclosure relates to fine spray nozzles, and more particularly to nozzles which create a vortex to form a fine spray.
2. Background of the Related Art
Traditionally, fine spray nozzles utilize either an impingement or an air-atomizing design to produce small droplets. Impingement is simply directing the flow of fluid through an orifice onto a pin to generate the spray. A primary disadvantage of impingement designs is that the target pin is difficult to align and can easily become damaged or misaligned resulting in poor performance. Moreover, a target pin may become dislodged and create damage downstream. Another drawback associated with impingement nozzles is that the orifice/pin feature tends to wear over the life of the nozzle which, in turn, may adversely affect spray pattern and drop size over the life of the nozzle. Air-atomizing designs are another well-known type of design which utilizes a source of pressurized air to atomize the fluid. A primary disadvantage of the air-atomizing designs is the increased expense of providing and maintaining the source of pressurized air.
In view of the above, several nozzles which utilize a swirling flow have been developed as alternatives. Swirling flow nozzles convert the head pressure of the fluid into kinetic energy within a swirl chamber. The swirling action causes the liquid to form into a thin, conical sheet that disintegrates into droplets under the action of aerodynamic and surface tension forces. Exemplary swirl flow nozzles are shown in U.S. Pat. Nos. 3,771,728; 3,532,271; and 6,186,417. Heretofore, several factors have limited the applicability of swirl flow nozzles, including: poor tolerance when machining the materials from which the nozzles are made; the spray patternation quality deteriorates as the size of the swirl chamber decreases; clogging due to smaller dimensions; and small parts become difficult to handle and assemble.
There is a need, therefore, for an improved small spray nozzle that overcomes one or more of the above-described drawbacks of the related art.